title: Interactions between halide anions and a molecular hydrophobic interface.
abstract: Interactions between halide ions (fluoride and iodide) and t-butyl alcohol (TBA) dissolved in water are probed using a recently developed hydration-shell spectroscopic technique and theoretical cluster and liquid calculations. High ignal-to-noise Raman spectroscopic measurements are combined with multivariate curve resolution (Raman-MCR) to reveal that while there is little interaction between aqueous fluoride ions and TBA, iodide ions break down the tetrahedral hydration-shell structure of TBA and produce a red-shift in its CH stretch frequency, in good agreement with the theoretical effective fragment potential (EFP) molecular dynamics simulations and hybrid quantum/EFP frequency calculations. The results imply that there is a significantly larger probability of finding iodide than fluoride in the first hydration shell of TBA, although the local iodide concentration is apparently not as high as in the surrounding bulk aqueous NaI solution.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana, USA.
authors.forename: Blake M
authors.initials: BM
authors.lastname: Rankin
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hands
authors.forename: David S
authors.initials: DS
authors.lastname: Wilcox
authors.forename: K Rebecca
authors.initials: KR
authors.lastname: Fega
authors.forename: Lyudmila V
authors.initials: LV
authors.lastname: Slipchenko
authors.forename: Dor
authors.initials: D
authors.lastname: Ben-Amotz
mesh_terms: D000838:Anions / Q000737:chemistry*; D006219:Halogens / Q000737:chemistry*; D006860:Hydrogen Bonding; D008962:Models, Theoretical; D013059:Spectrum Analysis, Raman
chemical_list: D000838:Anions; D006219:Halogens